They estimate Facebook will sell 600,000 Rift units this year and more than two million in 2017, generating over $1.6 billion in revenue from hardware and royalty fees from game sales.

Right now, Facebook makes almost all of its money from ads, but Cantor Fitzgerald sees Oculus slowly but steadily swelling the company's non-advertising revenue.

"Facebook is positioning itself at what we believe is the epicenter of a multi-year, multi-billion dollar growth opportunity in virtual reality," Cantor Fitzgerald analyst Youssef Squali writes. "While the adoption rate could be slow initially, with the platform attracting gamers at first, we estimate that virtual reality could account for ~10% of FB's overall revenues by 2020, and help sustain outsized revenue growth for the company for several years."

Here's a more detailed look at how Cantor Fitzgerald estimates Oculus' growth: